Search for supersymmetry in events with b-tagged jets and missing transverse momentum in pp collisions at s√=13 TeV with the ATLAS detector

Abstract

A search for the supersymmetric partners of the Standard Model bottom and top quarks is presented. The search uses 36.1 fb−1 of pp collision data at s√=13 TeV collected by the ATLAS experiment at the Large Hadron Collider. Direct production of pairs of bottom and top squarks (b̃1 and t̃1) is searched for in final states with b-tagged jets and missing transverse momentum. Distinctive selections are defined with either no charged leptons (electrons or muons) in the final state, or one charged lepton. The zero-lepton selection targets models in which the b̃1 is the lightest squark and decays via b̃1→bχ̃01, where χ̃01 is the lightest neutralino. The one-lepton final state targets models where bottom or top squarks are produced and can decay into multiple channels, b̃1→bχ̃01 and b̃1→tχ̃±1, or t̃1→tχ̃01 and t̃1→bχ̃±1, where χ̃±1 is the lightest chargino and the mass difference mχ̃±1−mχ̃01 is set to 1 GeV. No excess above the expected Standard Model background is observed. Exclusion limits at 95% confidence level on the mass of third-generation squarks are derived in various supersymmetry-inspired simplified models.